XJ550 Maxim Rebuild Project

Hi all! My name is Kelvin and I just picked up a used '82 XJ550 Maxim to try to fix up. It's in rough shape when I first got it and the carbs were out of the bike. I was told by the PO that the bike was running last year when he bought it but it doesn't want to run now. The bike turns but doesn't want to start. Was hoping to fix it up this winter and get it back on the road next summer.

Here's how she looked on the first day I got her:



So today my friend and I tried popping the carbs back in and indeed the bike doesn't want to start. Here a video showing how it sounds right now:



The bike was set on prime, choke turned on, fresh battery, fresh motor oil, new gasoline in the tank. We made sure the spark plugs/electrical was working as we took them out and tried starting with the plug against the body and we saw sparks.

Kind of stumped right now on what else we can try besides ripping everything apart. If you've watched the video above, there's this high pitched screech noise that's always there after we try to start the bike. It kind of sounds like metal on metal. Not sure if that's an indication of something broken inside the engine.

Any tips/pointers at this point would be awesome. Will take all suggestions and continue to update the thread as we try to fix this up.

Thanks everyone and I'm looking forward to my stay here!

 

That wouldn't be resistance of the piston in the cylinder wall, would it? If its anything like the 750 I have, how easy does the motor turn over via the the timing plate. Try that to see if there is a hard spot. I'd pull the head and check it out. After my disaster with the Seca, I'd check for internal damage.

 

have you cleaned the carbs yet?
did you confirm gas in carb bowls? open 1 of the drain screws if possible.
check your battery voltage sitting and while starting needs full charge to start if it droping to 10 volts or below tci will not work to fire spark

how long has bike sat?
did you put some penetrating oil in the cylinders to lube them and free up the rings?
if it were me I would stop and
1) I would read through the information over load
The Information Overload Hour

2) then church of clean
IN THE CHURCH OF CLEAN

3) compression test

4) valve clearance
AIRHEAD VALVE ADJUSTMENT with Pics

5) do you have a manual? sign up on this site www.4shared.com
http://www.4shared.com/rar/W7QZie6f/Yamaha_Xj550rh_Service_Repair_.htm

http://www.4shared.com/rar/VPkftmDj/Yamaha_Xj550rh_Service_Repair_.htm

lots of info thread at this link he is a parts supplier to
http://www.xjbikes.com/forums/forums/xj4ever-supporting-vendor.23/

this link too
http://www.xj4ever.com/downloads.html

wiring diagram book mark it
http://www.frankjohansson.com/stuff/xj550/XJ550ElectricalDiagram.html

 

have you tried a little starting fluid into the airbox?

there are 3 circuits in the carbs
the enrichment circuit (choke) it gets the bike started.
the Pilot circuit. it idles your bike and it works with the mixture screw (under the little aluminim cap you have to remove the cap)
The Main jets

The pilot fuel circuit is active from idle up to about 2500-3500 rpms, and at about 3000 rpms the main fuel circuit starts becoming involved, and by 4000+ rpms the main fuel circuit is responsible for about 80%+ of the engine's fuel supply conditions.

welcome to the site it is your best asset to get the bike up and running

you want to evaluate your motor first before spending money else where.
to do that you need compression test and valve check.
get those carbs clean per church of clean. it is suggested a complete break down of rack but can be done with out doing that. the throttle shaft seals can leak causing problems with idle .
if you brake down the rack you replace them if not you may have to replace them later when you get bike started if they leak. so it is a time now or time later thing. if you dip the carbs it will eat the seals .
when you are ready to start, ask questions in the tech forum before you start something,
my bike sat for 10 to 15 years found it inside of bushes growing up and around it .
runs link a charm now needs the cosmetics done this winter to make her shine but i am still riding my 550 I just cant bring my self to put it away for the winter

 

it sounds like you are not getting any fuel check your plugs to see if they are wet. also if you leave the key on for about 2 minutes the bike should back fire, this is a function of the tci to manage the coils. give that a try if no back fire probally no fuel flow

 

Thanks for the suggestion BK, I've read your thread and it sucks that you were sold a lemon from the PO. I'll keep your suggestion in mind if I can't get it running after checking the carbs a bit more.

Thanks for all the info XJ550H! Unfortunately the bike is at my friend's garage and I only have access to it over the weekend. I'll definitely check the carb bowls to make sure the the fuel is making it into the carbs. From what I remember the plugs were dry when I took them out half way through our attempts. Also the PO mentioned that the fuel feed lines in the carb was clogged so you might be right about no fuel making it into the engine.

By the way, what kind of lubricant is safe to put into the sparkplug holes? I've read WD40 and brake fluid but want to make sure before I throw anything in there that I would regret later down the road.

Thanks for the welcome guys!

 

to free up the rings
1part atf and 1 part acetone is the suggested home brew works well.
not wd 40
you could use Kroil penetrating oil or PB blaster penetrating oil

 

Always had luck with Kroil.

 

just found some at NAPA the other day. No one else has it in my area
poster is in BC so its hard to know what he has available to him for brands

 

Kroil, PBBlaster, snowmobile fogging oil, marvel mystery oil, motor oil, anything that will put put a thin oil film on the cyl walls. I dont even use WD anymore-- I've found that while it will initially disperse water, it will eventually attract it along with a lot more dirts

 

That sound is really odd... I'd think if it were a scraping cyl, you'd hear it ever stroke.... I'm wondering more about a valve, but regardless.... Do a compression test or a leakdown test.

 

Yeah I'm planning on doing a compression test this weekend. Will keep everyone updated on the findings.

 

Good news! Ran a compression test today and here are the results:

Cylinder 1: 135psi
Cylinder 2: 125psi
Cylinder 3: 125psi
Cylinder 4: 130psi

Pretty happy with the results. Healthy compression on all cylinders. Also put in 4 new NGK spark plugs today.

Confirmed that no fuel is making through the carbs so next thing is a full carb rebuild. That's most likely happening next week. Looking forward to getting this guy running again soon.

 

Sounds like a slipping starter clutch to me.

 

It's too tough to tell from a tiny screen and speaker on this phone. From MY vantage point it's a sound that I can duplicate on some of my instruments, as well as my voice---- which keeps me thinking air-flow related somehow. But I did make a similar sound drawing a finger across a balloon, so I'm not ruling out friction contact though. It's erratic enough that I can't narrow it down to a timing thing, but doesn't seem to be related to the starter system either, to my ear. It still sounds like an intermittent "exhaust horn" for lack of any better way to put it.

I'm stumped on this one, so I guess we have to see what turns out

 

That could be. I'm just relating it to what I've heard when the starter rollers catch just enough to spin the engine, and then don't disengage right away. I lived with that noise for a year before rebuilding mine (which does point to a bias on my part).

 

Interesting. I've only ever heard the " rattling rocks in a coffee can" sound when starter clutches go bad. I guess we'll see..... I've never heard this guy's sound before-----

 

Quick photo update on the carb cleaning process.
















So right now most of the carb is taken apart. Having troubles with the pilot jet. It's stuck in there pretty good. Tried some PB blaster and don't want to strip the screw head. Any suggestions in getting it out?

 

Close fitting screwdriver and some heat. I use a micro-torch

 

Would you torch it directly through the top or around the sides? Will attempt it tonight when I get home.

 

I carefully heat it around the outside of the riser. The metal expand slightly, and the residue softens so that with steady pressure it eventually softens enough to give in to the screwdriver torque.

 

Thanks for the clarification Dave. Wish me luck that I don't strip anything..!

 

Make sure the screwdriver is a perfect fit, otherwise you're almost guaranteed to strip it

Make sure to keep even pressure, but not horsing it either. Slow, steady, careful and cautious....

 

i had to grind down the sides of my screwdriver to fit in the hole but i had a spare pilot jet that i could fit to the screw driver for the proper fit
fill the shaft with your pb blaster let it soak in until you are set to take it out.
I had 1 pilot jet that was chewed out used a #1 easyout to get it out but i also soaked it for 4 days w.ith blaster.
i now have a can of kroil to use on my next set of carbs.
got it at napa 15$ 10oz can money back garentee if it does not work printed on the can also says not for retail sale
worked great on a few stuck screws

 

SHE'S ALIVE!!!!!!!!!

Got the bike running this weekend! Big milestone for this project. The bike is definitely not running at 100% though as it seems like we have a hanging idle issue. I've included a video below to show that. From what I've researched it points to a lean mixture. I've reset the idle mixture screw to 2.5 turns out but didn't help. As well the bike seems to have this weird buzz noise whenever I let go of the throttle. You can hear it in the video that I try to rev the RPM. I'm going to assume that's a by product of it running lean. Hopefully it goes away after I address all the potential issues. Other than that the bike idles rock solid at 1.2k.









I got a set of feeler gauges so will check the valve clearance next weekend. Oh yeah. the bike blew the exhaust collector when we first started her (see the black pieces under the bike in the idling video). Would that need to be replaced before we do any more work on the sync? Anyway, attaching some photos of the cleaned up carb parts as well as a couple videos. As always, any comments/suggestions always appreciated!

 

Sounds like a collectorbox chrome heatshield is rattling. Check the strap/bolt, and check the welds.

 

First of all, happy holidays to everyone that's been following my build. There's lots to update this time around so I'll try to go in order.

After letting the bike sit for a couple weeks since last working on it, it decides to not want to start anymore. Even more so, the carbs ended up flooding into the air intake box while I was trying to start it so I figured it's the right time to adjust the float level and fuel height.

Rigged a home made setup to keep the carbs nice and leveled while I worked on the tangs:





Made sure to level all four carbs, I think the manual said +/- 3mm, this was as close as I could get it without overflowing:



So after I got my carbs leveled and back into the Maxim, I was fully hoping that it would start. Butttttt, it didn't. So next thing on the list was a valve inspection and adjustment.

I took the valve cover off and measured all the spaces with my feeler gauges. BOY was I glad as all my valves were out of spec. And I mean every single one of them. So here are the data that I logged:

Cylinder 1:
E: 0.10mm Y280
I: 0.06mm Y280

Cylinder 2:
E: 0.08mm Y285
I: 0.04mm Y275

Cylinder 3:
E: 0.08mm Y280
I: 0.02mm Y285 (My gauge only went down to 0.04mm so I'm guessing it's at 0.02mm but it could very well be anywhere between 0.00mm and 0.03mm)

Cylinder 4:
E: 0.10mm Y270
I: 0.04mm Y280

It's considered in-spec if E: 0.16mm - 0.20mm and the I: 0.11mm - 0.15mm right?

So knowing that, I've decided I need to get the following replacement shims to get my valves in spec again:

Cylinder 1:
E: 0.10mm Y280 to Y270 => 0.20mm
I: 0.06mm Y280 to Y275 => 0.11mm (or should I go down to a Y270 and make it 0.16mm?)

Cylinder 2:
E: 0.08mm Y285 to Y275 => 0.18mm
I: 0.04mm Y275 to Y265 => 0.14mm

Cylinder 3:
E: 0.08mm Y280 to Y270 => 0.18mm
I: 0.02mm Y285 to Y275 => 0.12mm (or go down to Y270 as I'm not 100% sure what the gap is)

Cylinder 4:
E: 0.10mm Y270 to Y260 => 0.20mm
I: 0.04mm Y280 to Y270 =>0.14mm

I remember reading on the forum that I should always go for the larger gap if I had a choice as the gap will get smaller as it wears out. So applying that mind set I'll need the following shims:

Y260 x 1
Y265 x 1
Y270 x 5
Y275 x 1

I have one Y275 and one Y270 in my current pile, so I need to buy the following 6 shims?

Y260 x 1
Y265 x 1
Y270 x 4

Let me know if my logic runs correct. Also, I was told there's a shim pool in this forum that I can trade my shims in for another size? Who should I private message to get that process started? If not, where's the next best place to get the replacement shims I need?

Thanks everyone for reading so far. I'm hoping after I get the shims in the Maxim will run smoothly again!

 

Ill run your numbers again, and see what I have in the pool. Send me a private message, too--

 

Your shim changes are correct.... Will check swap needs after supper

 

Thanks Dave. Hope you're having a good holiday.

 

You need:
260 - 1
265 - 1
270 - 2
275 - 2

I'll see what I have when I go back out there this evening.

Blue = start and PUT IN
red = shims TAKEN OUT

 

wet set fuel level xj 550 -2mm +-1mm below carb mixing bowl body edge so 1 mm down to 3 mm down from edge.
e

 

Thanks! Looks like I'm working with the correct settings then.

 

Refresh my memory. When you cleaned the carbs did you replace the float needles, seats, and seat gaskets?

 

No nothing was replaced when I cleaned the carbs. Was hoping to clean it up without replacing anything yet.